Many children who are allergic to peanuts do not outgrow their allergy and have very severe allergic reactions called anaphylaxis. Symptoms of anaphylaxis include difficulty breathing, decreased blood pressure, hives, and lip or throat swelling after exposure to an allergen. A severe allergic reaction can lead to death if not treated appropriately.

The purpose of this study is to find out if there is a way to treat children with peanut allergy to help lower the risk of severe allergic reactions and also cause them to lose their allergy to peanuts. The approach that will used for this study is a process called "desensitization".

Oral immunotherapy involves eating gradually increasing amounts of a food over several months. This is a research study because at this time peanut oral immunotherapy (OIT) is investigational. Peanut OIT (study drug) is investigational because it is not currently approved for clinical use by the Food and Drug Administration. There are no alternative safe and effective treatments for peanut induced allergic reactions other than peanut avoidance and treatment with medications.

This is a phase I, open label study for the initial 12 month desensitization phase of peanut oral immunotherapy and a 2 year maintenance phase. Subjects will be recruited to determine the immune response during the administration of peanut OIT after the development of disease. Cohort will include children age 5-16 years who have peanut allergy. The study will require approximately 36 visits with 3 phases: screening phase (~ 2 months); build-up phase (weeks 1 year), followed by the maintenance phase (2 years).

The primary objective of the OIT protocol is to desensitize subjects to peanut and this occurs over the first 12 months of the study (build-up phase). The first dose will be based on the amount at which the subject reacted during a double blind placebo controlled food challenge (DBPCFC). Thereafter, dose escalation would continue as outlined in the protocol for approximately 50 weeks until the maintenance dose of peanut protein (3900 mg) is reached.

The maintenance phase will continue from the end of the build-up phase until approximately 24 months. During this phase, the subject will switch to a peanut equivalent dose for the maintenance phase. At the conclusion of the maintenance phase a DBPCFC will be done. Negative challenges will be confirmed by open challenge. DBPCFC will be done.

Inclusion Criteria:

• Age 5-16 years of either sex, any race, any ethnicity, weighing at least 18.3 kg at the time of the initial visit.
• The presence of Immunoglobulin E (IgE) specific to peanuts (a positive skin prick test to peanuts (diameter of wheal > 3.0 mm) and a positive in vitro IgE [CAP-FEIA] > 7 kUA/L) measured within the past year.
• Significant clinical symptoms occurring within 120 minutes after ingesting peanuts during an observed DBPCFC. Patients who have not had previous oral exposure to peanut will be observed for a longer duration of 150 minutes because they may demonstrate a delayed immune response, given the lack of prior peanut exposure. Also, patients with a history of prior anaphylaxis will be observed for 150 minutes.
• Provide signed informed consent.
• Ability to follow-up regularly for scheduled appointments.
• Subjects will not be excluded if they are primarily Spanish speaking.
• Females of childbearing potential must be willing to practice an acceptable form of birth control throughout the protocol.
• Epinephrine injection training provided. Participant has current in-date epinephrine injector and parent/guardian demonstrates proper use

Exclusion Criteria:

• History of severe anaphylaxis to peanut as defined by hypoxia, hypotension, or neurological compromise (Cyanosis or SpO2 < 92% at any stage, hypotension, confusion, collapse, loss of consciousness; or incontinence)
• Currently participating in a study using an investigational new drug.
• Participation in any interventional study for the treatment of food allergy in the past 12 months or while participating in this study.
• Poor control or persistent activation of atopic dermatitis.
• Diagnosis of persistent asthma as defined by NHLBI criteria and currently being treated with daily doses of inhaled corticosteroids or requiring a rescue inhaler more than 2 days per week.
• Inability to discontinue antihistamines for skin testing and Oral Food Challenges (OFCs).
• Pregnant female.
• Chronic medical condition requiring frequent use of oral steroids, chronic psychiatric illness or history of substance abuse.
• Active eosinophilic esophagitis requiring medication therapy during the past 12 months.
• Subjects with known oat or wheat allergy
• Subjects currently on the build-up phase of environmental allergy immunotherapy injections
• Live more than 175 miles away from Texas Children's Hospital located in the Medical Center.

Adverse event data were collected throughout the build up phase (ranged from 50-71 weeks for the eligible participants) and 2 years of the maintenance phase.